Moreover, this apparent controversial function of PPARβ/δ in cancer development is also illustrated in other cancer types for which several studies have suggested an attenuation of carcinogenesis by PPARβ/δ, while others support a tumour-promoting role (reviewed in Michalik et al, 2004; Peters & Gonzalez, 2009; Peters et al, 2012). Here, PPARD is linked to neoplasm.